I would only go if I were close to the person or if it required no travel.
Honestly, my DH and I and the majority of our family members are teachers as well, and even though I wanted a December wedding, I avoided it for a couple of reasons. One, because people seem to be really strapped during Christmas and I didn't want to add the financial expense of a wedding gift to people during that time. Two, because of people being unable to travel who I really wanted to take part of our day. Three, because of my parents' experience with having a December anniversary. It seems their anniversary is always overlooked and caught up with the Christmas hoopla. There's just too much to do during that time and it's stressful enough. They try to take time for themselves that day, but it just seems that it would be so much easier if it were further from Christmas.
If the couple were close to me, I would offer this advice and suggest the possibility of waiting until spring break a couple of months later. The weather in Florida is perfect, teachers are off, and it will always be a nice time to celebrate an anniversary. Yes, people may travel and not be able to attend, but 4/2013 is a ways away and those who want to attend would be able to make the necessary arrangements by that time.